The invention relates to metering guns or nozzles for dispensing a lubricating fluid.
In the field of vehicle service, handheld metering guns or nozzles are used to dispense predetermined amounts of a lubricating fluid, such as oil. The device has a lever that is squeezed against a handle to begin operation. The metering portion of the device then measures the amount of fluid passing through the device and closes a valve when a preset amount of the fluid has been dispensed. Such devices are useful in servicing vehicles using bulk supplies of oil or other lubricants. The device also has other industrial applications.
In the prior art, such devices have used mechanical metering mechanisms. These mechanisms have many parts that are subject to wear.
Electronic control offers a lower cost of manufacture, but to obtain these benefits, certain problems in converting to an electronic device must be overcome.
For convenience of use and mobility, such electronic devices must have their own power supply, typically provided by batteries. With batteries there are problems of battery life and assuring that the batteries do not fail with the valve in an open position.
An object of the present invention is to provide an electronically controlled metering device, which is less expensive to manufacture and easier to maintain than its mechanical predecessor. In addition, the device is to be protected from commencing a battery cycle when the battery is too low.
The invention is incorporated in a method and device for dispensing a lubricating fluid, in which the device is protected against low battery conditions, by disabling an electronically actuated latching device and relying on manual operation. An electronic control circuit monitors battery level and performs the disabling function when necessary as well as providing visual indications to the user. A manual override push button is also provided.
The device is conveniently programmable for multiple batch sizes and is operable in an automatic shut off mode.
Other objects and advantages of the invention, besides those discussed above, will be apparent to those of ordinary skill in the art from the description of the preferred embodiments which follow. In the description, reference is made to the accompanying drawings, which form a part hereof, and which illustrate examples of the invention. Such examples, however, are not exhaustive of the various embodiments of the invention, and therefore, reference is made to the claims which follow the description for determining the scope of the invention.